CHEYENNE, Wyo. (AP) -- Wyoming and the U.S. Department of Interior have reached an agreement over how to end federal protections for wolves in the state, officials announced Wednesday.

Gov. Matt Mead hailed the agreement, saying wolves have taken a heavy toll on livestock and wildlife in the state since they were reintroduced in the 1990s. Wyoming is the last state in the Northern Rockies that still has federal oversight of its wolf population.

"This is far from the end of this process, but I think we have come up with something that fits with Wyoming's values and economy," Mead said.

"For years ranchers and sheep producers have been asked to sacrifice, and they have. We have lost significant numbers of elk and moose, and we have not had a say in the management of an animal inside Wyoming," Mead said. "It's time for that to change. ..."

Interior Secretary Ken Salazar has traveled to Wyoming repeatedly in recent months to work on the agreement.

The gray wolf's recovery serves as a "great example" of how the Endangered Species Act can work to keep imperiled animals from becoming extinct, Salazar said Wednesday.

"The agreement we've reached with Wyoming recognizes the success of this iconic species and will ensure the long-term conservation of gray wolves," he said.

Environmental groups, however, decried the deal. They say it doesn't afford Wyoming wolves adequate protection and couldn't stand on its own merits if Congress fails to pass pending language to exempt it from legal challenges.

"We do think that it's important that wolf management decisions be based on science, and not on these kind of closed-door political negotiations," said Collette Adkins Giese, a lawyer with the Center for Biological Diversity in Minnesota. "That really does set a dangerous precedent for the Endangered Species Act."

Under the agreement, Wyoming would commit to maintaining at least 10 breeding pairs and 100 wolves outside Yellowstone National Park. There are now about 340 wolves in the state, of which 230 are outside the park.

Wolves immediately outside Yellowstone would be subject to regulated hunting in a zone that would expand slightly in the winter months to give wolves more protection in an area south of Jackson. Those in the rest of the state would be classified as predators that could be shot on sight.

Wyoming's commitment to classifying wolves as predators in most of the state has been a stumbling block to ending federal wolf management for years even as neighboring states have taken over their own wolf management.

Wyoming has filed several lawsuits over the issue, trying without success to force federal officials to accept its plan.

The U.S. Fish and Wildlife Service went as far as helping Wyoming revise its wolf management plan in 2007 and approving it the next year in a move that set the stage for the state to assume wolf management. However, the federal agency repudiated Wyoming's plan just months later after U.S. District Judge Donald Molloy of Missoula, Mont., criticized it in response to a lawsuit brought by environmental groups.

Wyoming's shoot-on-sight policy continues to generate controversy. Massachusetts Rep. Ed Markey announced Wednesday that he had written to Salazar questioning his decision to reach a deal with the state.

"The backbone of the Endangered Species Act has always been its commitment to use science to protect species from extinction," wrote Markey, the ranking Democrat on the House Natural Resources Committee. "Science, not politics, should ensure the conservation and management of the gray wolves in Wyoming, should they be delisted."

Rep. Cynthia Lummis, R-Wyo., has inserted language into a pending Interior appropriations bill that would specify that any delisting of wolves in Wyoming would be exempt from court challenges.

"For years, Wyoming has worked in good faith to produce and defend a wolf management plan," Lummis said. "These labors have been difficult and frankly haven't produced results -- until today."

Congress approved similar language earlier this year for delisting wolves in Montana, Idaho and other western states except Wyoming. Some environmental groups are mounting a legal challenge in Molloy's court to exempting those wolf delisting actions from legal review.

Steve Ferrell, Mead's policy adviser on endangered species, said Wednesday that Wyoming hopes Congress will act to stipulate that any final delisting plan will be exempt from legal challenges.

Ferrell said the federal government plans to propose a draft delisting rule by Oct. 1. He said it could take a year for the final rule to be approved to allow Wyoming to take over wolf management.

The Wyoming Legislature will consider changes to the state's current wolf management plan when it meets early next year.

Chris Colligan, Wyoming wildlife advocate for the Greater Yellowstone Coalition, said Wednesday he believes the push to exempt the agreement from legal review shows the deal is politically motivated and not supported by sound science.

"It says that Wyoming and certainly our congressional representatives, they know that this plan is not legally or biologically sufficient," he said.